History of Flight
On February 15, 2012, at approximately 0154 Pacific standard time, a Cessna 172S, registration N665SP, impacted terrain on the western face of Mount Si, near North Bend, Washington. The airplane was registered to Christiansen Aviation Inc. of Wilmington, Delaware, and was operated by the pilot under Title 14 Code of Federal Regulations Part 91. The commercial pilot and two passengers sustained fatal injuries. Dark night visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Renton Municipal Airport (RNT) at 0135.
A witness, a rated private pilot, reported observing the airplane's anti-collision and navigation lights as it flew low, about 1 mile north of Interstate 90. The witness lost sight briefly but reestablished visual contact near North Bend, where the airplane altered course to a northeasterly direction at an estimated altitude of 1,000 feet above ground level. Visibility was at least 3 miles with a high overcast ceiling and a few lower clouds. Several witnesses near the accident site heard an impact sound; one reported seeing the airplane's lights at 300 to 500 feet agl, then hearing the engine rev up, followed by a pop and the engine noise stopping.
FAA radar data showed the airplane climbing from RNT to 2,400 feet msl, then descending to 1,500 feet msl near Snoqualmie Falls. The last radar target was at 0146, about 1.5 miles southwest of the falls at 1,500 feet msl, approximately 6.11 miles northwest of the accident site. According to a passenger's family member, the pilot and passengers attended a hockey game starting at 1930 and then went to dinner.
Personnel Information
The pilot, aged 30, held a commercial pilot certificate with single- and multi-engine land and instrument ratings, as well as a flight instructor certificate with the same ratings. A first-class medical certificate was issued on August 8, 2007, with no limitations. The pilot's logbook showed 991.5 total flight hours as of February 12, 2012.
Aircraft Information
The airplane was a four-seat, high-wing, fixed-gear Cessna 172S, serial number 172S8069, manufactured in 1998. It was powered by a Lycoming IO-360-L2A engine (180 horsepower) with a McCauley fixed-pitch propeller. The most recent annual inspection was completed on October 10, 2011, at an airframe total time of 5,477.3 hours and engine time since major overhaul of 560.7 hours.
Meteorological Information
Automated weather observations from Renton Municipal Airport (21 miles east of the accident site) at 0756 reported wind from 160 degrees at 5 knots, visibility 6 miles, mist, few clouds at 2,800 feet, an overcast layer at 4,000 feet, temperature 2°C, dew point 2°C, and an altimeter setting of 30.25 inches of mercury.
Wreckage and Impact Information
The airplane impacted trees and terrain on an approximate heading of 120 degrees magnetic at an elevation of about 1,958 feet msl. Multiple topped trees and damaged limbs were found in the debris path. Both wings, horizontal and vertical stabilizers separated; the fuselage came to rest inverted with the engine attached. Partial flight control cable continuity was established; rudder cables remained attached, aileron and flap cables showed tension overload separations, and the flap actuator indicated a 0-degree flap setting. Elevator cables separated consistent with stabilizer separation; the elevator trim actuator measured 1.3 inches (neutral trim). The top spark plug from cylinder 2 exhibited normal wear. The fuel distribution valve showed no debris or damage. The propeller separated from the crankshaft with leading edge polishing and S-bending. No evidence of mechanical malfunction or failure was found. The wreckage was not recovered.
Medical and Pathological Information
An autopsy by the King County Medical Examiner on February 16, 2012, determined the cause of death as blunt force trauma. Toxicology tests by the FAA's Civil Aeromedical Institute detected ethanol in urine (246 mg/dL), vitreous (195 mg/dL), and blood (154 mg/dL). Acetaminophen was found in urine (92.08 µg/mL), and diphenhydramine was detected in blood (6.852 µg/mL) and in urine and liver (unspecified amount). CAMI noted that 14 CFR 91.17 prohibits acting as a crewmember with 0.040 g/dL or more alcohol in the blood, and adverse symptoms can occur at 20.0 mg/dL.